// GtkSharp.Generation.MethodBody.cs - The MethodBody Generation Class.
//
// Author: Mike Kestner <mkestner@speakeasy.net>
//
// Copyright (c) 2001-2003 Mike Kestner
// Copyright (c) 2003-2004 Novell, Inc.
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of version 2 of the GNU General Public
// License as published by the Free Software Foundation.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public
// License along with this program; if not, write to the
// Free Software Foundation, Inc., 59 Temple Place - Suite 330,
// Boston, MA 02111-1307, USA.


namespace GtkSharp.Generation {

	using System;
	using System.Collections;
	using System.IO;
	using System.Linq;

	public class MethodBody {

		Parameters parameters;
		LogWriter log;

		public MethodBody(Parameters parms, LogWriter _log) {
			parameters = parms;
			log = _log;
		}

		private string CastFromInt(string type) {
			return type != "int" ? "(" + type + ") " : "";
		}

		public string GetCallString(bool is_set) {
			if (parameters.Count == 0)
				return String.Empty;

			string[] result = new string[parameters.Count];
			for (int i = 0; i < parameters.Count; i++) {
				Parameter p = parameters[i];
				IGeneratable igen = p.Generatable;

				bool is_prop = is_set && i == 0;

				if (i > 0 && parameters[i - 1].IsString && p.IsLength && p.PassAs == String.Empty) {
					string string_name = (i == 1 && is_set) ? "value" : parameters[i - 1].Name;
					result[i] = igen.CallByName(CastFromInt(p.CSType) + "System.Text.Encoding.UTF8.GetByteCount (" + string_name + ")");
					continue;
				}

				if (is_prop)
					p.CallName = "value";
				else
					p.CallName = p.Name;
				string call_parm = p.CallString;

				if (p.IsUserData && parameters.IsHidden(p) && !parameters.HideData &&
					   (i == 0 || parameters[i - 1].Scope != "notified")) {
					call_parm = "IntPtr.Zero";
				}

				result[i] += call_parm;
			}

			return String.Join(", ", result);
		}

		public void Initialize(GenerationInfo gen_info) {
			Initialize(gen_info, false, false, String.Empty);
		}

		public void Initialize(GenerationInfo gen_info, bool is_get, bool is_set, string indent) {
			if (parameters.Count == 0)
				return;

			StreamWriter sw = gen_info.Writer;
			for (int i = 0; i < parameters.Count; i++) {
				Parameter p = parameters[i];

				IGeneratable gen = p.Generatable;
				string name = p.Name;
				if (is_set)
					name = "value";

				p.CallName = name;
				foreach (string prep in p.Prepare)
					sw.WriteLine(indent + "\t\t\t" + prep);

				if (gen is CallbackGen) {
					CallbackGen cbgen = gen as CallbackGen;
					string wrapper = cbgen.GenWrapper(gen_info);

					Parameter closureParam = null;
					if (p.Closure != -1) {
						closureParam = parameters[p.Closure];
					}
					Parameter destroyNotifyParam = null;
					if (p.DestroyNotify != -1) {
						destroyNotifyParam = parameters[p.DestroyNotify];
					}

					if (p.Scope == "notified" && destroyNotifyParam == null && closureParam == null) {
						closureParam = parameters[i + 1];
						destroyNotifyParam = parameters[i + 2];
					}

					switch (p.Scope) {
						case "notified": {
								sw.WriteLine(indent + "\t\t\t{0} {1}_wrapper = new {0} ({1});", wrapper, name);
								if (closureParam != null) {
									sw.WriteLine(indent + "\t\t\tIntPtr {0};", closureParam.Name);
								}
								if (destroyNotifyParam != null) {
									sw.WriteLine(indent + "\t\t\t{0} {1};", destroyNotifyParam.CSType, destroyNotifyParam.Name);
								}
								sw.WriteLine(indent + "\t\t\tif ({0} == null) {{", name);
								if (closureParam != null) {
									sw.WriteLine(indent + "\t\t\t\t{0} = IntPtr.Zero;", closureParam.Name);
								}
								if (destroyNotifyParam != null) {
									sw.WriteLine(indent + "\t\t\t\t{0} = null;", destroyNotifyParam.Name);
								}
								sw.WriteLine(indent + "\t\t\t} else {");
								if (closureParam != null) {
									sw.WriteLine(indent + "\t\t\t\t{0} = (IntPtr) GCHandle.Alloc ({1}_wrapper);", closureParam.Name, name);
								}
								if (destroyNotifyParam != null) {
									sw.WriteLine(indent + "\t\t\t\t{0} = GLib.DestroyHelper.NotifyHandler;", destroyNotifyParam.Name, destroyNotifyParam.CSType);
								}
								sw.WriteLine(indent + "\t\t\t}");
								break;
							}
						case "async":
							sw.WriteLine(indent + "\t\t\t{0} {1}_wrapper = new {0} ({1});", wrapper, name);
							sw.WriteLine(indent + "\t\t\t{0}_wrapper.PersistUntilCalled ();", name);
							break;
						case "call":
						default:
							if (p.Scope == String.Empty)
								log.Warn(gen_info.CurrentMember + " - defaulting " + gen.Name + " param to 'call' scope. Specify callback scope (call|async|notified) attribute with fixup.");
							sw.WriteLine(indent + "\t\t\t{0} {1}_wrapper = new {0} ({1});", wrapper, name);
							break;
					}
				}
			}

			if (ThrowsException)
				sw.WriteLine(indent + "\t\t\tIntPtr error = IntPtr.Zero;");
		}

		public void InitAccessor(StreamWriter sw, Signature sig, string indent) {
			sw.WriteLine(indent + "\t\t\t" + sig.AccessorType + " " + sig.AccessorName + ";");
		}

		public void Finish(StreamWriter sw, string indent) {
			foreach (Parameter p in parameters) {
				if (parameters.IsHidden(p))
					continue;
				foreach (string s in p.Finish)
					sw.WriteLine(indent + "\t\t\t" + s);
			}
		}

		public void FinishAccessor(StreamWriter sw, Signature sig, string indent) {
			sw.WriteLine(indent + "\t\t\treturn " + sig.AccessorName + ";");
		}

		public void HandleException(StreamWriter sw, string indent) {
			if (!ThrowsException)
				return;
			sw.WriteLine(indent + "\t\t\tif (error != IntPtr.Zero) throw new GLib.GException (error);");
		}

		public bool ThrowsException {
			get {
				int idx = parameters.Count - 1;

				while (idx >= 0) {
					if (parameters[idx].IsUserData)
						idx--;
					else if (parameters[idx].CType == "GError**")
						return true;
					else
						break;
				}
				return false;
			}
		}
	}
}